Presence of MHC-I and B-7 molecules in rat and human glioma cells expressing antisense IGF-I mRNA

Tumor cells frequently express the insulin-like growth factor I (IGF-I). Recently we demonstrated that rat glioma cells when transfected with a vector encoding antisense IGF-I cDNA lost tumorigenicity and induced a tumor specific immune response involving CD8+ lymphocytes. Here we show that the cultured transfected cell lines, rat C-6 glioma, human primary glioma and mouse teratocarcinoma, expressed an increased level of MHC-I and of co-signaling B-7 molecules. This increased expression of MHC-I and B-7, demonstrated by 51Cr release complement dependent cytoxicity assay and by immunostaining flow cytometry analysis, could contribute to the final immune recognition of glioma immunogenicity.